There has been recent concern that completely halogenated chlorofluorocarbons might be detrimental toward the Earth's ozone layer. Consequently, there is a world-wide effort to use halogen-substituted hydrocarbons which contain fewer chlorine substituents. For example, 1,1,1,2-tetrafluoroethane (HFC-134a), a hydrofluorocarbon having zero ozone depletion potential, is being considered as a replacement for dichlorodifluoromethane (CFC-12) in refrigeration systems. The production of hydrofluorocarbons (i.e., compounds containing only carbon, hydrogen and fluorine) has been the subject of renewed interest to provide environmentally desirable products for use as solvents, blowing agents, refrigerants, cleaning agents, aerosol propellants, heat transfer media, dielectrics, fire extinguishants and power cycle working fluids (see, e.g., PCT International Publication No. WO93/02150).